Nature’s Notebook

Connecting People with Nature to Benefit Our Changing Planet

You are here

Cloned Dogwoods

You're invited to participate in the Cloned Plants Project by obtaining a cloned Cloned Plants Program logo dogwood and reporting phenology observations via Nature's Notebook. You can also participate by tracking a native flowering dogwood that is already established in your yard.

Why Clones?

dogwood flowersA maple tree in New York blooms later than a maple tree in Georgia. Why? Is it that both trees bloom when it's been warmer than 40 degrees Farenheit for 3 weeks? Or are there genetic differences between the trees? One way to tease these influences apart is by planting genetically identical plants, or clones, in different locations, and then to observe when they leaf out and flower. When observations are made on cloned plants, you can know with confidence that differences in the timing of phenological events between different individuals is due to differences in local environmental conditions.

Volunteers have been tracking cloned lilacs for over 50 years, and these observations have been invaluable for documenting how plants are responding to a variable and changing climate. Learn more. However, lilacs don't grow very well in the southernmost parts of the US. A dogwood was recently cloned for distribution in southeastern states to address part of this data gap, and Nature's Notebook participants began submitting observations in 2013.

Consider contributing to this valuable effort by tracking a cloned dogwood (Cornus florida 'Appalachian Spring'). View the map to find out whether dogwoods grow where you live. To acquire a cloned dogwood plant, view the list of local cloned dogwood distributors, or inquire at your local nursery. We are also interested in observations of cloned lilacs; if you live outside of the dogwood distribution, a cloned lilac might be best for you. See what volunteers' observations of cloned dogwoods are revealing.

How to participate...

1. Mark your cloned plants.

If you received cloned dogwoods from us prevously, check our guide on dogwood planting and care.

If you prefer to track plants which are already established at your site, we also welcome observations on the native flowering dogwood (Cornus florida)

2. Join Nature's Notebook. If you haven't already, create a Nature's Notebook account. See our specifics of observing if you need more details on getting started. Make sure you register your dogwoods as the clone Cornus florida 'Appalachian Spring' when adding the plants to your site. 

3. Observe your plant(s). Report what you see (yes/no/not sure) on your plant periodically following the instructions for cloned dogwoods. We encourage you to observe your plant(s) 2-4 times a week, especially in the spring, when things are changing rapidly. However, we welcome any observations you can contribute.

We are especially interested in the following phenophases, although you are welcome to track all of the phenophases for this species. We have also included some photos to help you identify some of the more tricky phenophases:

Breaking leaf buds One or more breaking leaf buds are visible on the plant. A leaf bud is considered "breaking" once a green leaf tip is visible at the end of the bud, but before the first leaf from the bud has unfolded to expose the leaf stalk (petiole) or leaf base. Breaking leaf bud, Photo: Josh Sayers
Leaves One or more live, unfolded leaves are visible on the plant. A leaf is considered "unfolded" once its entire length has emerged from the breaking bud so that the leaf stalk (petiole) or leaf base is visible at its point of attachment to the stem. Do not include fully dried or dead leaves.  
Increasing leaf size A majority of leaves on the plant have not yet reached their full size and are still growing larger. Do not include new leaves that continue to emerge at the ends of elongating stems throughout the growing season.  Increasing leaf size, Photo: CJ Tsai, Dogwood Genome Project
Flower buds One or more fresh open or unopened flowers or flower buds are visible on the plant. Include flower buds that are still developing, but do not include wilted or dried flowers. As soon as the overwintering flower buds begin to swell, you can start reporting "yes" to flowers or flower buds Flower buds, Photo: Dennis Brown, Wikimedia Commons
Open flowers One or more open, fresh flowers are visible on the plant. Flowers are considered "open" when the reproductive parts (male stamens or female pistils) are visible between or within unfolded or open flower parts (petals, floral tubes or sepals). Do not include wilted or dried flowers. For Cornus florida 'Appalachian Spring', ignore the four large, white bracts and watch for the opening of the small flowers in the center of the bracts'. Remember, you should continue to report "yes" to flowers or flower buds (above) when you report "yes" to open flowers. Open flowers, Photo: Dcrjsr, Wikimedia Commons

 

How do I tell a leaf bud from a flower bud? Leaf buds (left photo) and flower buds (right photo) can be tricky to identify. If you think you have misidentified a flower or leaf bud, you can correct your submitted observations. Learn more here. Also, remember that the "flowers" you are looking for are actually the small yellow/green flowers inside the large white bracts. In dogwoods, flower buds generally start to open before leaf buds. 

Leaf buds, Photo: S.Seiberling UNC Herbarium Flower buds, Photo: Derek Ramsey, Wikimedia Commons

 

4. Report your observations. Periodically log into your Nature's Notebook account and transfer your observations from your paper data sheet into the online reporting system. Alternatively, you can enter your observations directly using our Android or iPhone smartphone and tablet apps.


2016 RESULTS FROM THE Cloned DOGWOOD CAMPAIGN

How did dogwoods respond in 2016, and was it different from 2015? Phenology calendars can provide a picture of when phenophases were reported over the year. Colored bars on the phenology calendars below indicate that an observer reported "yes" for breaking leaf buds and open flowers, while gray bars indicate an observer reported "no." 

In 2015, the majority of breaking leaf buds for cloned dogwoods were reported in late March, while in 2016, the majority were reported over a week earlier. We see a similar trend for leaves. There were several reports of flowers or flower buds made in the winter of 2015. These are likely the dormant flower buds that dogwoods put on in the fall. Remember, you should not start reporting "yes" to flowers or flower buds until the dormant buds start to swell. 

cloned dogwood breaking leaf buds and flowering 2015-16


Cloned plants program roots

Lilacs at NASA Goddard Space Flight Center

For over 50 years cooperators in the United States and Canada have assisted phenological researchers by making phenological observations on cloned lilacs and honeysuckles. This program has now been incorporated into the USA-NPN's Cloned Plants Project. Previously it had been part of the University of Wisconsin-Milwaukee's Indicator Observation Program. In addition to the cloned and common lilac, some participants in the UWM program observed cloned honeysuckle Lonicera tatarica 'Arnold Red'. Due to its invasive nature, honeysuckles have not been distributed to observers since 1987. The USA-NPN does not distribute the honeysuckle nor support its distribution. The USA-NPN does accept observations from historically established cloned honeysuckles. Find out more about the Cloned Plants Project and its history.

Share this content.